the SharpMap.Presentation.WinForms.MapViewControl has a WorldHeight property. It returns the height of the view in units of the underlying data. If you need e.g. meters and your data is lat/lon, you need to setup a projection.

If your data is Lat/Lon you need to define a projection (for example Google World Mercator EPSG:900913 or an UTM-Zone projection covering your area) and then project the Maps current Envelope to that projection. Then the Height property will contain you
views height in meters.

If your projection is already meterbased you only need to use the MapHeight property of the Map.

After aplied my transformation, i have got my Height(in metres), but my map became blank (and i called map.ZoomToExtents() and extends is not null), but after some steps my map is shown normal. This steps are:

1. Many clicks on the map with ZoomOut tool.

2. Recall mapViewControl1.ZoomToExtents(),

(don't ask me how i found this way))

plese help me to fix that. i want a normal map after first mapViewControl1.ZoomToExtents() call.